Public Sub Invalidate() 

Dim instance As RasterImageListItem
 
instance.Invalidate()

public void Invalidate()

public:
void Invalidate(); 

''' 
Private Sub SelectImageListItem(ByVal imageList As RasterImageList, ByVal itemIndex As Integer)
   ' Loop through all the items in the list
   Dim i As Integer = 0
   Do While i < imageList.Items.Count
      Dim item As RasterImageListItem = imageList.Items(i)
      ' If this is not out item and is selected, de-select it
      If i <> itemIndex AndAlso item.Selected Then
         item.Selected = False

         ' re-paint only this item
         item.Invalidate()
      End If

      ' If this is our item and is not selected already, select it
      If i = itemIndex AndAlso (Not item.Selected) Then
         item.Selected = True

         ' re-paint only this item
         item.Invalidate()
      End If
      i += 1
   Loop
End Sub

/// 
private void SelectImageListItem(RasterImageList imageList, int itemIndex)
{
   // Loop through all the items in the list
   for (int i = 0; i < imageList.Items.Count; i++)
   {
      RasterImageListItem item = imageList.Items[i];
      // If this is not out item and is selected, de-select it
      if (i != itemIndex && item.Selected)
      {
         item.Selected = false;

         // re-paint only this item
         item.Invalidate();
      }

      // If this is our item and is not selected already, select it
      if (i == itemIndex && !item.Selected)
      {
         item.Selected = true;

         // re-paint only this item
         item.Invalidate();
      }
   }
}